Network switches are used for data centers and large corporate offices and provide a number of services, such as 1 gigabit Ethernet (GbE), 10 GbE, and optical network links. These applications often require high availability (HA) features such as two or more redundant power supplies (RPSs) for each network switch to provide maximum uptime for the network. RPS units may be mounted internally or externally and can be load-sharing, hot-swappable, and field-replaceable to maintain uninterrupted operation. In the case of multiple network switches mounted together or a reasonable distance apart, the RPS power budget, i.e., the total backup power that the RPS units may sustain, may be pooled and shared over the multiple switches.
The total available RPS power is typically pooled in a central RPS which provides backup power to a group of the switches within a multi-switch network. Usually, there is not enough backup power from the RPS to drive all of the network switches in the event of a power failure of one or more of the power supplies. When needed, backup power is allocated first to the highest priority switches and on down to the lowest priority switches. In this case, power is typically allocated to the switches based on a total power requirement for each of the switches. That is, the total required power for each switch in a multi-switch network is typically used to determine the priority levels in assigning backup power to the network switches in the event of a power failure. The highest power switches and devices are often granted the highest priority for backup power. For example, the different switches within the multi-switch network may have dissimilar power budgets, typically ranging from 200 W for basic network switches up to 1400 W for more complex switches. As a result, the network switches with the lowest power requirements may be prevented from receiving power from the RPS during times of high demand for backup power. There may also be low priority switches with high priority ports, such as critical network equipment, security cameras, or important telephone equipment, that do not receive power in the event of a power failure.